CN107792655B

CN107792655B - Workpiece taking-out system

Info

Publication number: CN107792655B
Application number: CN201710743949.4A
Authority: CN
Inventors: 加藤贤明; 上田哲士
Original assignee: Fanuc Corp
Current assignee: Fanuc Corp
Priority date: 2016-08-29
Filing date: 2017-08-25
Publication date: 2020-07-24
Anticipated expiration: 2037-08-25
Also published as: DE102017214816B4; DE102017214816A1; US10493627B2; JP6599827B2; JP2018034213A; CN107792655A; US20180056514A1

Abstract

The invention provides a workpiece taking-out system (1), which comprises: a conveyor (2) that conveys a plurality of workpieces (W) in one conveying direction; a position detection unit (7) that detects the conveyance position of the workpiece (W) by the conveyor (2); a distribution robot (3) that follows the movement of the conveyor (2) by linear tracking based on the detected conveyance position and rearranges the workpieces (W) conveyed in one row by the conveyor (2) into two rows according to a predetermined rule; and a pair of take-out robots (4, 5) that follow the movement of the conveyor (2) by linear tracking based on the conveyance position detected by the position detection unit (7), and that take out only the workpieces (W) in any row rearranged by the allocation robot (3) within the movement range, wherein the pair of take-out robots (4, 5) are arranged side by side in a direction orthogonal to the conveyance direction of the conveyor (2).

Description

Workpiece taking-out system

Technical Field

The invention relates to a workpiece removal system.

Background

Conventionally, a work takeout system has been known in which a plurality of takeout robots are provided at intervals in a conveying direction of a work on a conveyor in order to take out the work carried in a row by the conveyor from the conveyor to a plurality of takeout destinations according to a predetermined rule, and each robot follows a linear path of the movement of the conveyor to take out and transfer the work on the conveyor to the takeout destination (for example, see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2007-30087

Disclosure of Invention

Problems to be solved by the invention

However, when a plurality of robots are arranged as in patent document 1, if linear tracking areas based on the respective robots overlap, mutual linkage is required, and a loss occurs in cycle time. In order to avoid this, it is necessary to dispose the robots away from each other in the conveying direction of the workpiece on the conveyor so that the linear tracking areas of the robots do not overlap each other, and there is a problem that the length of the conveyor must be ensured to be longer as the number of the pickup locations increases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a workpiece takeout system that can reduce the length of a line and save space even if the number of takeout destinations of workpieces transported in a line on a conveyor increases.

Means for solving the problems

In order to achieve the above object, the present invention provides the following aspects.

One aspect of the present invention provides a work pickup system including: a conveyor that conveys a plurality of workpieces in one conveying direction; a position detection unit that detects a conveyance position of the workpiece by the conveyor; a distribution robot that follows the movement of the conveyor by linear tracking based on the conveyance position detected by the position detection unit and rearranges the workpieces conveyed in one row by the conveyor into two rows according to a predetermined rule; and a pair of pickup robots that follow the movement of the conveyor by linear tracking based on the conveyance position detected by the position detection unit, and that pick up the workpieces by placing only the workpieces in any one of the rows rearranged by the allocation robot within a movement range, wherein the pair of pickup robots are placed side by side in a direction orthogonal to the conveyance direction of the conveyor.

According to this aspect, when the workpieces are conveyed in one row by the conveyor, the workpieces are rearranged into two rows by the dispensing robot disposed on the upstream side. Since the pair of take-out robots disposed downstream are disposed side by side in the direction orthogonal to the conveying direction of the conveyor, the length of the line can be kept short.

In this case, since the pair of picking robots dispose only one or only the other of the two rows of workpieces within the operation range, the pair of picking robots do not need to be interlocked with each other, and can operate efficiently without losing cycle time.

In the above aspect, the dispensing robot and the take-out robot may be provided above the conveyor in a suspended state.

Thus, the space above the wide conveyor capable of conveying two rows of workpieces can be effectively utilized, and the increase of the width of the assembly line can be suppressed.

In the above aspect, the robot system may further include a camera which is disposed upstream of the dispensing robot and photographs the workpiece, and the dispensing robot and the picking robot may track the workpiece based on the conveying position detected by the position detecting unit and the image of the workpiece acquired by the camera.

In this way, even when the postures of the workpieces conveyed in a row on the conveyor are not uniform, the motions of the dispensing robot and the takeout robot can be corrected in a manner of imitating the postures of the workpieces on the basis of the images of the workpieces acquired by the cameras, and the workpieces can be conveyed reliably.

In the above aspect, the distribution robot may divide the workpieces conveyed in one row by the conveyor into two types, and may move and rearrange only the workpieces belonging to one classification into two rows.

By doing so, the number of workpieces conveyed by the dispensing robot can be reduced, the conveying speed of the conveyor can be increased, and the workpieces can be taken out more efficiently.

Effects of the invention

According to the present invention, even if the number of takeout destinations of workpieces conveyed in a row on a conveyor increases, the length of a line can be suppressed and space can be saved.

Drawings

Fig. 1 is a plan view showing a workpiece picking system according to an embodiment of the present invention.

Fig. 2 is a plan view showing an example of a conventional system as a comparative example of the work picking system of fig. 1.

Fig. 3 is a plan view showing another example of a conventional system as a comparative example of the work picking system of fig. 1.

Fig. 4 is a plan view showing a first modification of the work removing system of fig. 1.

Fig. 5 is a plan view showing a second modification of the work removing system of fig. 1.

Description of the reference numerals

1 workpiece taking-out system

2 conveyor

3 dispensing robot

4. 5 taking out robot

7 encoder (position detecting part)

8 vidicon

W workpiece

Detailed Description

A workpiece picking system 1 according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in fig. 1, the work picking system 1 according to the present embodiment includes: a conveyor 2 that conveys the workpiece W in one conveying direction; a distribution robot 3 that distributes a plurality of workpieces W conveyed in a single row on the conveyor 2 into two rows; a pair of take-out robots 4 and 5 disposed downstream of the dispensing robot 3; and a control unit 6 for controlling the

robots

3, 4, and 5.

The dispensing robot 3 and the pair of take-out robots 4 and 5 are suspended six-axis articulated robots provided above the conveyor 2, and have a hand, not shown, at the tip of an arm for gripping the workpiece W.

The distribution robot 3 is disposed substantially at the center in the width direction (direction orthogonal to the conveying direction) of the conveyor 2. The pair of take-out robots 4 and 5 are arranged side by side in the width direction of the conveyor 2.

The arrangement positions of the dispensing robot 3 and the pair of take-out robots 4 and 5 are set so that the operation range of the dispensing robot 3 for gripping the workpiece W by hand, including the workpiece W, and the operation range of the take-out robots 4 and 5 for gripping the workpiece W by hand, including the workpiece W, do not overlap with each other.

The conveyor 2 includes an encoder (position detecting unit) 7 for detecting the movement amount of the conveyor 2. By mounting the workpiece W on the conveyor 2 at a predetermined timing, the conveyance position of the workpiece W can be detected only by the movement amount of the conveyor 2 detected by the encoder 7.

The control unit 6 performs linear tracking based on the information on the conveying position of the workpiece W detected by the encoder 7, and causes the dispensing robot 3 and the pair of pickup robots 4 and 5 to follow the workpiece W conveyed by the conveyor 2.

Thus, the dispensing robot 3 and the picking robots 4 and 5 follow the movement of the workpiece W conveyed by the conveyor 2, grasp the workpiece W with a hand, and rearrange or pick the workpiece W.

As shown in fig. 1, the pair of pickup robots 4 and 5 dispose the workpiece W picked up from the conveyor 2 at a pickup position A, B, and the position A, B is disposed downstream of the most downstream position of the conveyor 2.

Here, the conveyor 2 conveys the workpieces W in a state of being aligned in a row. The dispensing robot 3 rearranges the works W in one row into two rows according to a predetermined rule. The predetermined rule may be arbitrary, but predetermined conditions such as the kind, weight, and size of the workpiece W can be adopted.

The operation of the work unloading system 1 according to the present embodiment configured as described above will be described.

In order to pick out a workpiece W carried by the conveyor 2 in two types using the workpiece picking system 1 according to the present embodiment, a plurality of workpieces W arranged within the operating range of one picking robot 4 and outside the operating range of the other picking robot 5 are conveyed in a row by the conveyor 2 in a direction aligned with the conveying direction of the conveyor 2.

Since the workpiece W first passes through the operation range of the dispensing robot 3 disposed on the upstream side, the control unit 6 causes the dispensing robot 3 to follow the operation of the conveyor 2 by linear tracking based on the information of the conveying position transmitted from the encoder of the conveyor 2 and the information determined by a predetermined rule, and causes the dispensing robot 3 to hold only the workpiece W conforming to the rule. The workpieces W that do not meet the above-described rules are conveyed by the conveyor 2 as they are.

Then, the control unit 6 changes the conveying path of the conveyor 2 so that the dispensing robot 3 conveys the gripped workpiece W and passes through the operating range of one of the takeout robots 4 and the operating range of the other takeout robot 5. Thus, the workpieces W conveyed in one row are rearranged into two rows.

At this time, the dispensing robot 3 changes, for example, only the position of the workpiece W in the width direction on the conveyor 2, and moves the position in the conveying direction by linear tracking so as to coincide with the home position.

Thus, the pair of takeout robots 4 and 5 can grasp the workpiece W conveyed to the own operation range and take out the workpiece W to the takeout destination by the linear tracking of the control unit 6 based on the information of the conveyance position conveyed by the conveyor 2.

As described above, according to the workpiece takeout system 1 of the present embodiment, there is no need to arrange the two takeout robots 4 and 5 side by side in the conveying direction of the conveyor 2, and the linear tracking region along the conveying direction of the conveyor 2 is shared by the two takeout robots 4 and 5, which has an advantage that the length of the line can be shortened. That is, in the conventional method in which the take-out robots 11 and 12 are arranged side by side in the conveying direction of the workpiece W on the conveyor 2, as shown in fig. 2 or 3, in order to prevent a loss of the cycle time due to the interlocking, it is necessary to provide the take-out robots 11 and 12 away from each other in the conveying direction of the workpiece W on the conveyor 2 so that the linear tracking areas of the two take-out robots 11 and 12 do not overlap each other, and the length of the line becomes long.

In contrast, according to the workpiece takeout system 1 of the present embodiment, the conveyance paths of the workpieces W are divided so that the operating ranges of the two takeout robots 4 and 5 do not overlap each other, thereby preventing a loss of cycle time due to the interlocking, and the takeout robots 4 and 5 can be disposed at substantially the same position in the conveyance direction of the workpieces W by the conveyor 2, thereby shortening the length of the line. Further, since the takeout destinations of the workpieces W by the takeout robots 4 and 5 are arranged on the downstream side of the most downstream side of the conveyor 2, there is an advantage that the line width can be reduced.

Further, since the

robots

3, 4, and 5 are suspended above the conveyor 2, the space above the conveyor 2, which is wide and can convey two rows of workpieces W, can be effectively used, and the increase in the width of the flow line can be further suppressed.

In the present embodiment, the workpiece W is conveyed by the conveyor 2 in a row so as to pass through the operating range of one of the takeout robots 4 and out of the operating range of the other takeout robot 5. Thus, the dispensing robot 3 can process the workpiece W by changing only the conveying path of the workpiece W taken out by the other taking-out robot 5, and can convey the workpiece W at a higher speed.

Instead, as shown in fig. 4, the workpieces W may be conveyed in a row so as to pass through the substantial center in the width direction of the conveyor 2, and all the workpieces W may be conveyed and distributed by the distribution robot 3 so that all the workpieces W pass through the respective operation ranges of the two take-out robots 4 and 5.

As shown in fig. 5, a camera 8 may be disposed above the conveyor 2 on the upstream side of the dispensing robot 3, and the camera 8 may photograph the workpiece W conveyed by the conveyor 2. The control unit 6 controls the

robots

3, 4, and 5 by visual tracking based on the image acquired by the camera 8 and information on the conveying position of the workpiece W detected by the encoder 7 of the conveyor 2.

As shown in fig. 5, even when the workpieces W are not aligned and are transported in various postures, the

robots

3, 4, and 5 can grip and transport the workpieces W. In particular, the handling workpieces W carried by the dispensing robot 3 can be aligned in an easy-to-hold posture by the take-out robots 4 and 5 in the subsequent process, and there is an advantage that the handling workpieces W can be efficiently taken out by avoiding an unnecessary operation of the take-out robots 4 and 5.

In the present embodiment, the case where two pair of picking robots are provided is exemplified, but the present invention may be applied to a workpiece picking system having three or more picking robots instead of the above-described one. In the present embodiment, the dispensing robot 3 and the pair of takeout robots 4 and 5 are suspension type six-axis articulated robots, but the present invention is not limited to this, and may be robots placed on a suspended robot stand or on a shelf, for example, or articulated robots other than six-axis robots such as five-axis robots or seven-axis robots, for example.

Claims

1. A workpiece take-out system is characterized by comprising:

a conveyor that conveys a plurality of workpieces in one conveying direction;

a position detection unit that detects a conveyance position of the workpiece by the conveyor;

a distribution robot that follows the movement of the conveyor by linear tracking based on the conveyance position detected by the position detection unit and rearranges the workpieces conveyed in one row by the conveyor into two rows according to a predetermined rule; and

a pair of take-out robots that take out the workpieces while placing only the workpieces in any one of the rows rearranged by the allocation robot within an operation range while following the operation of the conveyor by linear tracking based on the conveyance position detected by the position detection unit,

the pair of the take-out robots are arranged side by side in a direction orthogonal to the conveying direction of the conveyor.

2. The workpiece retrieval system of claim 1,

the dispensing robot and the take-out robot are disposed above the conveyor in a suspended state.

3. The workpiece takeout system according to claim 1 or 2, further comprising:

a camera disposed on an upstream side of the dispensing robot and configured to photograph the workpiece,

the dispensing robot and the picking robot track the workpiece based on the conveyance position detected by the position detecting unit and the image of the workpiece acquired by the camera.

4. The workpiece retrieval system according to claim 1 or 2,

the distribution robot divides the workpieces conveyed in one row by the conveyor into two categories, and moves and rearranges only the workpieces belonging to one category into two rows.

5. The workpiece retrieval system of claim 3,